In relation to OLED (Organic Light-Emitting Diode) or PLED (Polymer Light-Emitting Diode), the method for forming an organic film includes:
(1) a vacuum deposition process which is applicable to small organic molecules and characterized in that an organic film can be formed without a solvent to have a uniform thickness, but with disadvantages of high equipment investment, low material utilization and incapability of manufacturing large-sized products; and
(2) solution-related method, including spin coating, ink-jet printing, nozzle coating method, applicable to polymer materials and small soluble molecules, which is characterized by low equipment costs, and prominent performance on large-scale, large-sized production. In particular, the ink-jet printing technology enables a solution to be precisely ink-jetted into a pixel region to thereby form an organic film. But the biggest difficulty lies in that the organic solution in the pixel area can hardly form an organic film having a uniform thickness.